Earplug



FIG. 1 illustrates an isometric view of the design for the earplug.

FIG. 2 illustrates a side view thereof, all other side views displaying the same image thereof.

FIG. 3 illustrates a bottom view thereof; and,

FIG. 4 illustrates a top view thereof.

The broken lines shown in the drawing are only provided to illustrate the environment of the design. 

The ornamental design for an earplug, as shown and described. 